There are several types of paintball equipment used while playing a game of paintball. Many of them serve important functions like providing safety, while some of them may be intended for cosmetic purposes only. There are also some nifty paintball accessories which can really come in handy when playing the game.
Paintball Gun:
Paintball guns are replicas of actual firearms used to mark an opposing player with paint in the popular game of paintball. These guns propel paintballs through a barrel with a muzzle velocity of approximately 300 ft/s to break upon impact. Different types of paintball guns have different firing system such as Electro-pneumatic, mechanical, or gas-powered firing systems.

Some of the more popular paintball guns include semi-automatic, stock class and pump guns.
Safety Equipment:
Paintball Mask:
Paintball Masks protect the face by covering the eyes, mouths, ears and nostrils. Some masks are also equipped with throat guards. Lenses which come in double-layered or thermal designs are more reliable and the air chamber between the outer and inner lens prevent fogging. High end mask products should be considered while playing paintball because most of them are designed to effectively halt speeding paintballs which normally travel at a speed of 200 to 300 ft/s.

Polycarbonate or Lexan provides good impact resistance so be sure to check if the mask has lens made with those.
Barrel cover:
A barrel plug is normally a neoprene pouch attached over the barrel opening by a cord. This safety device prevents accidentally fired paintballs to cause any harm by blocking exit. A barrel sock is more effective in reducing the possibility of the safety equipment being detached from the marker/gun barrel.
Cleaning Equipment:
Squeegees:
The barrel or breach of the paintball gun may collect dust or paintball debris. Squeegees, hinge-mounted rubber discs on the end of plastic rods, are used to clean these out by inserting the rubber end into the barrel. Cable squeegees, in which the rubber disc is mounted perpendicularly on the end of the cable, used to clean open breech and removable bolt paintball guns.
Battle Swab:
This is a double ended stick, with a bendable rubber section in the middle, which has a soft absorbent fur which is shoved down the length of the barrel to remove paint debris or paintball shell.
Common Accessories:
Drop forward and Rail:
Drop forwards, which is attached to the bottom of the gun, drop the tank a few inches and move it forward. This makes the paintball marker/gun taller but shorter in length.

Safety features may include on/off switch. Another alternative to drop forward, which has become more popular, is the rail system which enables a tank regulator to be mounted directly at the base of the grip.
Remote line:
Remote lines are cables attached to the tank from the paintball marker/gun so that user can easily move while handling the marker/gun.
Pod:
These are plastic containers that can hold about 140 to 200 paintballs. Pods may be equipped with springs at the top for quick opening, locking mechanism to prevent accidental opening, and shock absorbers to prevent paintballs from breaking.
Harness:
A harness, which holds the pods, provides the player with a convenient supply of paint. They may also be fitted with a pouch to hold the tank during a remote setup, a bellyband with hoops in the back for the pods and pockets for maps, radios, and hydration pouches.